Endoprostheses have an axis and comprise a structure suitable for adopting a first, radially deployed, state in a situation implanted in the passageway, or a second, radially restricted, state in a positioning situation, for example inside an intraluminal introduction sleeve. In practice, such implants may comprise especially an occlusion device or vascular device, a blood filter having limbs, or even a stent for the treatment of stenosis, or a prosthesis for the treatment of an aneurysm.
At present, difficulties are sometimes encountered in placing an implant in its closed state inside its introduction sleeve, especially when the implant is small. Likewise, when an implant of the temporary or temporary/permanent type is positioned inside a passageway, it is necessary to be able to hold or detach the implant with respect to its introduction system, and even to be able to recover it after having released it.